To provide a high-end tandem printer system restricted in costs, not complicated in a paper sheet route, and capable of preventing fall of productivity at 100% even if one of machines is broken down.

The tandem printing system is structured of two printers and a dual finisher station 300 arranged between them. Each of printers has a sheet feeder, a sheet transporter, a device for printing an image on the sheet supplied from the sheet feeder through the sheet transporter, and a fuser for fusing the image onto the sheet. The dual finisher station 300 includes a finisher 310 connected to a first machine, a finisher 350 connected to a second machine, and a common catch tray 335 arranged between them. The finisher 350 is arranged by turning at 180° from a standard arrangement of the finisher 310.